A method of manufacturing a piezoelectric microactuator assembly can include forming a top electrode layer onto a top face of a PZT element and placing a mask at different locations on the top electrode layer. A conductive epoxy can be added in the space between the at least two portions of the mask, and a constraint layer can be applied to the conductive epoxy smaller than the top electrode layer formed on the PZT element. The mask ca be removed, leaving the constraint layer on the conductive epoxy, creating an exposed shelf of the top electrode uncovered by the constraint layer. A bottom electrode layer can be formed onto a bottom face of the PZT element opposite the top electrode layer and the PZT element can be polarized to form an active piezoelectric layer.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A method of manufacturing a piezoelectric microactuator assembly, the method comprising: forming a top electrode layer onto a first face of a PZT element; placing at least two separate portions of a mask at different locations over a top surface of the top electrode layer; applying a constraint layer over the mask, wherein the constraint layer is smaller than the top electrode layer formed on the PZT element; removing the mask and leaving the constraint layer, exposing at least two portions of the top electrode and creating an exposed shelf from any of the at least two exposed portions of the top electrode that are uncovered by the constraint layer; forming a bottom electrode layer onto a bottom face of the PZT element opposite the top electrode layer; and polarizing the PZT element to form an active piezoelectric layer.
2. The method of claim 1, further comprising placing the PZT element onto a first transfer tape prior to forming the top electrode layer.
3. The method of claim 1, wherein the top electrode layer is formed by sputtering and/or electrodeposition.
4. The method of claim 1, wherein the constraint layer includes unpoled piezoelectric material.
5. The method of claim 1, wherein the constraint layer includes a stainless steel layer.
6. The method of claim 1, further comprising applying a second transfer tape to the constraint layer after applying the constraint layer to the conductive epoxy.
7. The method of claim 1, wherein the bottom electrode layer is formed by sputtering and/or electrodeposition.
8. The method of claim 1, wherein the constraint layer has a Young's modulus of greater than 100 GPa.
9. The method of claim 1, further comprising disposing and electrically bonding an electrical connection to the active piezoelectric layer on the exposed shelf.
10. The method of claim 1, further comprising: applying a voltage to the active piezoelectric layer, wherein the active piezoelectric layer is actuated by the voltage that causes the active piezoelectric layer to expand and bend in a direction that causes the first face of the PZT element to become net concave in shape.
11. The method of claim 1, further comprising: applying a voltage to the active piezoelectric layer, wherein the active piezoelectric layer is actuated by the voltage that causes the active piezoelectric layer to contract and bend in a direction that causes the first face of the PZT element to become net convex in shape.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
March 14, 2022
February 18, 2025
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